Electric range circuit



Aug. 24, 1943. R. T. FRAzu-:R

ELECTRIC RANGE CIRCUIT Filed Feb. 7, 1941 QOLOMJWW L @Gr pdb:

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UNITED STATES PATENT OFFICE aszisz ELECTRIC RANGE CIRCUIT Robert T. Frazier, Chattanooga, Tenn., assigner to Cavalier Corporation, Chattanooga, Tenn., a corporation of Tennessee Application February 7, 1941, Serial N0. 377,909

2 Claims.

This invention is a novel improvement in electric range circuits particularly adapted for use in electric stoves or ranges fordomestic use or the like; and one object thereof is to provide an electric range having a plurality of surface heating units connected in circuit with a kmulti-heat selector connected across the power input leads, said selector having pairs of outlet terminals controlled by individual rmanually adjustable means for regulating the percentage of on-andoff time at each of said pairs of loutlet terminals, whereby any desiredy degree of heat within the limits of the capacity of the circuit from oil to high can be imparted to the individual surface heating units, by merely adjusting said manual means, the use of the multi-selector vbeing a bigV improvement over the usual electric range circuit in which the heating units are controlled merely by manual switches adapted to be adjusted to give only three or four different degrees of heat. p

A further object oi the invention is to provide a range circuit vof the above type having a convenience outlet connected across one pair of outlet terminals of the multi-heat selector, whereby varying degrees of 4heat within the limits of the capacity of the circuit from oifto high can be imparted to the convenience outlet in the same manner as above stated with-respect to the surface heating units.

A further object of the invention iste providel a clock-actuated timer adapted to cleseand open the multi-heat selector circuit of the above described type at predetermined times, together with switch means for manually connecting and disconnecting said timer from said selector circuit, whereby when the electric timer is connected in the selector circuit any of the surface heating units, or the convenience outlet, whose selector dials are in on position, will havey their individual circuits opened and closed at predetermined times by said timer. l

A further object of the invention is to provide an electric range circuit including an electric deep-well cooker connected across the power input leads, and an electric oven provided with the customary manual switch connected across said lead, and a plurality ci surface heating units connected across the leads, said circuit also including a three-pole double-throw switch having the set of poles at one side lthereof connected to one power input lead, and said circuit also including a single pole timer,` with the set `of poles of the switch at the other side thereof connected through the timer to the same power input lead, the movable contacts of the switch being respectively connected in the circuits of the cooker, `oven and surface units, together with means for simultaneously engaging all ofthe movable contacts with the first set of switch -poles so that each-of ythe ovenfcooker and surface heating unit circuits can be simultaneously and individually manually controlled, together with means for selectively engaging the movable switch contacts with their related poles of the second set of the switch while retaining the other n movable contcts engaged with the iirst set of poles, whereby the cooker, oven, or surface units can be individually automatically controlled by the timer without affecting the manual operation of the other circuits of the range.

A further object of the invention is to provide the electric range circuit set forth in the preceding paragraph, with a multi-heat selector connected across 'the power input leads With one lead of the selector connected to its related movable Contact of the double-throw switch, said multi-heat selector having pairs oi outlet terminals to which the surface heating units are respectively connected, and having manually operable dials for varying within the capacity of the circuit the amperage across said pairs of outlet terminals.

A still further object is to provide the circuit as set forth in the preceding paragraph, in which a convenience outlet is connected across one pair of the youtlet terminals of the multi-heat selector.

I will explain the invention with reference to the accompanying drawing which illustrates one practical embodiment thereof to enable others familiar with the art to adopt and use the same; and will summarize in the claims the essential features of the invention, and novel combinations of parts, for which protection is desired.

The drawing illustrates, conventionally, an electric range circuit according to my invention.

As conventionally shown in the drawing, my circuit includes a terminal block l which serves as a junction for the various individual circuits, said block having a pair of hot terminals la, Ib, bridged by a jumper lx; also a pair of neutral terminals Ic, id, bridged by a fuse ly (of about l5 ampere rating), and a second pair of hot terminals le, I f, bridged by a jumper la. Terminals la, Ic and Ic of said block are respectively connected to the leads AJ N and B respectively of a 240 volt three-wire power line, the lead N being the neutral wire.

A timer switch 2 of conventional electric` single-pole clock-driven type has one terminal 2a or the Clock motor directly connected by wire 3 to neutral terminal lc oi block I, the other clock motor terminal 2b being directly connected by wire to hot terminal if of block l. Said timer switch 2 has a movable contact 2c connected by wire 2e to wire 4, -said contact being normally spaced'from a fixed Contact 2d adapted to be opened and closed at predetermined times by the action of .the clock mechanism in the usual mandouble-throw type is provided in the circuit,

same being actuated by a disk cam a of nonconducting material mounted on a shaft 5b and rotated by a conventional dial (not shown) into one of four different positions respectively denoted manual, cooken surface units and outlet and .oven. Cam 5a has a flat side 5am, as shown, and three leaf springs 5c, 5d, 5c ride the periphery of cam 5a, said springs each'being V-shaped with one end anchored on the switch and their apeXes respectivelyA contacting said cam at points disposed approximately 90 apart around the periphery thereof, leaving one arc of about 180 clear. The dotted positions of the springs in the drawing indicate their respective positions when contacting the flat side 5am of the cam, while the full-line positions of the springs indicate their positions when contacting the rounded periphery of cam 5a.

The free end of spring 5c carries a movable contact 5f between spaced fixed contacts 5g, 5h; similarlyY spring 5d carries a movable contact 5i between fixed contacts 57, ic; and similarly spring 5c carries a movable Contact 5l between fixed contacts 5m, En. In the position of cam 5a shown in the drawing the switch dial is in socalled manual position and each of the springs tic, 5d, 5e is contacting the rounded periphery of the cam 5a thus closing the pairs of switch contacts 5f, 5g; 5i, 5j; and 5l, 5m. However, as cam 5a is rotated in a clockwise direction through successive 90 turns, the flat portion 5am of the cam will come opposite the apeXes of springs 5c,

lid and 5c successively and their related movable contacts will be shifted towards the shaft 5b to engage their related inner fixed contacts 5h, 5k and En successively to close their related circuits, two of the three springs in any of the four positions of cam 5a, except that shown in the drawing, riding the rounded periphery of the Vcam, so that only one of the movable contacts 5f, iii or 5l can in any position of the cam other than that shown in the drawing contact its related fixed contact 5h, 5k or im. Therefore, when cam 5a is rotated in a clockwise direction 90 from the position shown in the drawing, the pairs of contacts 5f, 5h and 51,57' and 5l, 5m, will be closed. Further rotation of the cam 90 will close the pairs of contacts 5f, 5g and 5i, 5k: and 5l, 5m. Still further rotation of cam 5a through 90 will close the pairs of contacts 5f, tlg and 5i, 5j and 5l, 5m'. The next rotation of cam 5a through 90 will restore the cam and springs to the positions shown in full lines in the drawing.

Terminal 5o of selector switch 5 is connected by wire 6 to hot terminal |f of block l; and each of the fixed contacts 5g, 5:1' and 5m are connected by wire 'I to contact 5o. Terminal 5p of selector switch 5 is connected by wire 8 to each of the fixed contacts 5h, 5k and 5u; and a wire 9 connects terminal 5p to fixed contact 2d of timer 2, whereby when timer contacts 2c, A2d are closed the terminal 5p will be connected through wires 9, 2e and i directly to the same hot terminal if of block to which wire 5 is connected.

A multi-heat selector l0 is provided in the circuit, the same being preferably of the type shown and described in U. S. Letters Patent No. 2,194,585 dated March 26, 1940, issued to Tuttle & Kift, Inc., and therefore needs no particular description herein. The selector i has a 110 volt synchronous motor Illa` driving an internal shaft on which four cams'are disposed, each cam actuating a pair of contacts which allow the 240 volt current to ow from the selector I to the individual surface units and convenience outlet.

Each pair of contacts is made variable by adjusting individual dials to various positions which in reality vary the clearance between the contacts,

thus varying the amount of times the current flows from a constant flow at high position to an intermittent ow lasting but a few seconds on the lowest position. Motor lila runs only when any one or more dials of the selector are vturned on.

|01' connects one terminal of pilot |017 with post Idd onthe selector which post is connected as above described to hot terminal lb of block I; and the other terminal of pilot Ilb is connected by wire IDs to post IBh which latter is connected to neutral post lc of block l. Thus pilot light |011 for the convenience outlet 29 and the surface units S', S2 and S3 operates on the same circuit as the motor Ia thus glowing when any said unit 1s on.

The multi-heat selector l0 has one pair of outlet terminals |02', |07`, connected by wires |6 and |'l respectively to the terminals I8, l0, of one surface heating unit S', whereby the current to the heating unit can be varied by rotation of the dial #1 of selector l0; also a second set of terminals llc and |01 similarly connected by conductors 20 and 2| to the terminals 22 and 23 of the Second surface heating unit S2 for variably controlling the current to said coil by adjusting the dial #2 of selector I0; also a third set of outlet terminals Hlm, |011 connected by conductors 24, 25 respectively to the terminals 2t and 21 of a third surface heating unit 23, whereby a variable amount of current can be passed through the heating unit by adjusting the dial #3 of selector Ill.

The selector I0 is also provided with a contact lp connected by wire 28 to one terminal of a convenience outlet 29, the other terminal thereof being connected by a wire 30 to the terminal Id of block said terminal being connected through fuse Iy to the other neutral terminal |c of block l and from thence by wire I5 to the post lh of the selector l0. The dial #4 of selector I!! is thus connected internally to vary the amperage of the 120 volt current passing to convenience outlet 2S.

To illustrate an example of a circuit through the multi-heat selector I6; if it is desired to turn the surface heating unit S3 on highj dial #3 of the selector is turned into high position thereby immediately actuating motor |0a and causing pilot Ib to glow. The 240 volt current from outlet terminals |0111, and |011. on the multiheat selector l0 will energize the heating element of unit S3 through conductors 24 and 25, since the pairs of outlet contacts on the multiheat selector |0 for the three surface heater units S', S2, S3, and for the convenience outlet 2!! obtain their 240 volt current on one side from post Illp through wires I2 and I3 leading directly to one hot terminal |b` of block l; and on the other side from post |03: on selector I0 lector switch 5 and from thence tothe movable contact 5i on spring 5d, which contact 5i when engaging fixed contact 51' of switch 5is connected directly to terminal 5o of said switch and fromthence by wire 6 directly to the other hot terminal I f of block Iv. However, if movable contact 5i of switch 5 should be contacting the fixed contact 5k (instead of contact 5j) the wire 3|- would be connect/ed through wires 8, 9, through closed contacts 2c, 2d of timer 2, and through Wires 2e and 4 directly to the same hot terminal If of blocl;` I. Preferably a filter condenser 32 is connected across the power input leads I2 and 3| of the multi-heat selector I0 to prevent radio interference which might be caused by arcing at the selector contacts.

The deep well cooker C is operated by a conventional six-pole switch 33 in order to impart thereto iive diierent degrees ofl heat. Cooker C has three terminals 34, 35 and 36 connected to the ends and middle respectively of its heating element; and cooker switch 33 has three contacts 3l, 38 and 39 respectively which are energized through various contact positions in the switch from the switch terminals 49, 4I and 42. Switch contact 31 is connected to one end terminal 34 of the cooker by wire 4-3; switch contact 38 is connected to` the opposite end terminal 36 of the cooker by wire 44; and' switch contact 39 is connected to the intermediate cooker terminal 35'by wire 45. Switch terminal 42 is connected by wire 4S directly to neutral terminal Ib of block I; switch terminal 4I is connected directly by wire 41 to one hot terminal Ib of block I; and switch terminal 45 is connected by wire 48 to spring 5c of switch 5, andY hence to movable contact 5j thereof which when contacting iixed contact 5g of switch 5 is connected throughwires 'I and 6 directly to the other hot terminal If of block I'. However, in event movable contact 5f of switch 5 should be engaging Xed contact 5h (instead oi?V 5g) of switch 5, then wire 4B would be connected through contact 5f, and through wires 8 and 9, through closed contacts 2c, 2d, of timer 2, and through wires 2e and 4 directly to the same hot terminal I f of block I-.

The oven utilizes a conventional hook up for a two-unit five-heat thermostatically controlled circuit. The bottom oven unit 49 has one heating element 50, and the top oven unit 5I has two separate heating elements 52 and 53; The oven circuit includes a Vswitch 54 having six poles adapted to give iive different degrees oi heat, also a thermostat 55 of the two-pole single throw. hydraulically operated type. A neon pilot lamp 56 is connected in the thermostat circuit and is energized when the thermostat contacts are closed, a pilot circuit having a resistor 5`|- connected in series with the` filament of the neon bulb 56 to lower the voltage across said pilot bulb.

The oven circuit receives current through wire 58 leading to oven switch terminal 54a directly from hot terminal Ib of block I; also through wire 59 leading from contact 54h of switch 54 to terminal 55a of thermostat 55 and through the internal wiring of said thermostat to terminal 55o thereof, which terminal 55D is connected by wire S to the movable contact 5l of spring 5e of selector switch 5, from contact l to fixed Contact 5m, so that when spring 5e is in the position shown in full lines in the drawing the circuit will be completed, and from thence through wires 1 and 6 directly to the other hot terminal I f of block However, if movable contact 5l is in contact with the other fixed contact 511 oi switch 5, then thel circuit from contact 5l is completed to the same hot terminal If of block I through wires 8, 9, through closed contact 2c, 2d of timer 2, and through wires 2e and 4 to block terminal I f. A wire 6I connects` the neutral terminal 54e of oven switch 54 directly to the neutral terminal Ic of block l. The heating element oi the bottom oven unit 49 is connected by wire S2 to the terminal 54d of oven switch 54, and is also connected by wire 53 to the common terminal 52a of `the top oven unit 5I, which common terminal is connected by wire 54 to the terminal o of the thermostat. The heating element 52 inthe top oven unit 5I has one end connected to the common terminal 5Ia and its other end connected by wire S5 to pole 54e of oven switch 54. The other heating element 53 oi the top oven unit 5I has one end connected to the common terminal 5 Ia. and its other end connected by wire 5B to thel terminal 54j of oven switch 54. Pole 54g of oven switch 54 is connected by wire 61 to the terminal 55d of thermostat 55. The pilot 55 is connected by wire 68 through resistor 51 to the hot thermostat terminal 55h and also connected by wire 69 to the terminal 55o oi said thermostat.

The use of selector switch 5 permits the operator of the range to connect any one of separate circuits of the cooker C, of the surface heating units S', S2, S3 and convenience outlet 29, and cf the oven 4Sf-5i into the circuit of automatic timer 2, any one of which said circuits can be set to be closed at any predetermined time, not to exceed twelve hours from the time the timer 2 is actually set, and to thereafter permit said desired circuit to operate for a period not to exceed twelve hours, and then to be antoniatically turned eff. During this time any of the other remaining circuits may be used in the normal manner without in any way eiecting the circuit which is automatically time controlled by y timer 2.

Operation In the position of the springs 5c, 5d, 5c of selector switch 5 shown in full lines in the draw-- ing, the movable contacts 5f, 5i, and 5l are each held in Contact with the iixed contacts 5g, 57' and 5m respectively, and the timer 2 is therefore disconnected from the circuits of cooker C, of sur.- face units S', S2, S3 and of convenience outlet 29, and of oven 49, 5I, and thus cooker C can be manually controlled by actuating the dial of cooker switch 33 to provide any of the five different stages or degrees of heat while switch 33 is turned 011. Also the surface heating units S', S2 and S3 and the convenience outlet 29 can be manually controlled by adjusting their respective dials #1, #2, #3 and #4 of multi-heat selector I0 to send any desired amperage' through their respective circuits when any of the said dials are on. Also the oven 49, 5I can be controlled manually by switch 54 and thermostat 55V to give any of the desired different stages or degrees of heat while the switch 54 is in any of the on positions.

If the iibre cam 5a, is turned by the selector switch dial in a clockwise direction through an arc of the at portion 5am of cam 5a will be engaged by spring 5c which will then be shifted into thel position shown in dotted lines in the drawing, thereby closing contacts 5f, 5h, andthe circuit ofv cooker C from hot contact I f of block l will be completed through wires il, 2d, through closed contacts 2c, l201,05 timer 2, and through wires il and 3 to the cocker switch 33, and through wirell'l to the other hot terminal lb of block l, so that the timer 2 may be set to close, maintain and open the circuit or" cooker Cat predetermined times irrespective ci the setting of the dial of cooker switch 33 into any on position. The pairs of selector switch contacts Ei, 5y' and 5l, tm however are maintained by the rounded periphery of cam 5a in their respective manual positions, and therefore the timer circuit will not aiect the surface heating units S', S2 and S3 and convenience outlet 29, or of the oven iQ-5l, which continue to be subject to manual control the salme as when the cam ta is in the position shown in full lines in the drawing.

A further rotation o fibre cam 5a in a clockwise direction through an arc of 90 will bring the :dat side liar thereof into contact with the spring 5d, thereby engaging movable contact 5i with fixed contact 5k, as shown in dotted lines in the drawing, said contact 57a being connected by wires il and Q, through closed timer co-ntacts 2c, 2d, and through wires 2e and Il to hot contact lf of block l. Then if the operator wishes to heat an electric percolator using theY convenience outlet 29, and assuming it is nine oclock in the evening and he wishes hot coi-lee to be prepared by seven oclock the following morning, he knowing that it requires about fifteen minutes total time to percolate the coffee, the operator will in such position of the cam 5a of switch 5 set the timer 2 to close the contacts 2c, 2d at 6:45 a. ni. and to open said contacts at 7 a. In. Dial #4 of multi-heat selector lll which controls the amperage of outlet 2Q is then turned to highl and the percolator plugged into outlet 29. The following steps then take place in completing the automatic Set up: The timer clock operating constantly will close timer contacts 2c, 2d at 6:45 a. in. to complete the circuit from outlet 29 on one side through wire d to neutral terminal ld of block l, and on the other side through wire 2t to contact lllp ofV selector ld, then internally through the selector lil to contact tr of selector iii and from thence through wire 3l vto movable contact 5i of selector switch 5, to Xed contact 5k, through wire 3 to switch contact 5p, and through wire il and through closed contacts 2c, 2d, through wires 2e and i to hot terminal if of block l. After the elapse of fifteen minutes the clock motor of timer will cause the contacts 2c, 2d to open, thereby opening the circuit and stopping the current iiow to outlet 29 and to the percolator. During thetime the selector switch and timer are set to operate, the remaining surface heating units of the range S', S2, S3 can be operated manually in the normal manner without interference, but will be also subject to the action of timer 2. In such position of cam 5o however the lpairs of switch contacts 5f, 5g, and ill, 5m remain closed as shown in full lines in the drawing, and therefore the cooker C, and oven 9, 5l can be operated manually as above described, independently of the timer 2.

If the bre cam 5a is rotated in a clockwise direction through another arc of 90 the flat side 5am thereof will engage spring 5e of switch 5 thereby closing contacts El, En, as shown in dotted lines in the drawing, thus bringing the timer 2 into circuit with the oven lll), 5| through wires 8 land 9, closed contacts 2c, 2d, and wires 2e and Ll. lThus in a similar manner the oven circuit can be controlled by the automatic timer 2 to close and open at predetermined times, when oven switch 54 is turned into any of the on po-v sitions. tacts 5f, 5g and 5l, 5m remain closed as shown in iull lines inthe drawing, the cooker circuit, and the circuit for the surface units 'and convenience outlet will remain manually controllable as above explained while the oven circuit is automatically controlled by timer 2.

I do notV limit my invention to theexact circuit shown in the drawing, for obviously changes may be made therein within the scope of the claims.

I claim:

l. In lan electric range circuit; power input leads including a neutral wire and two hot wires; a plurality of separate heating unit circuits including manual switches `connected across said leads; a multi-pole double-throw switch having one set of xed poles connected to one hot wire; a single pole timer; the other Xed Ipoles oi the switch being connected through the timer to the same hot wire; the movable poles of the switch being respectively connected in the separate heating unit circuits means for selectively engaging minals; and a convenience outlet having one lead any one of the movable poles of the switch with its related iixed pole of the second set while retaining the other movable poles of the switch engaged with their related fixed poles ofthe first set; a motor; one oi said separate circuits including a plurality of multi-heat Selectors operated by said motor and connected acrosslsaid hot wires through the related movable switch pole, each selector having a pair oi' outlet terminals; manually controlled means in said selectors for varying the average thermal output over a period of time across each oi' said pairs of outlet terminals; range heating units connected respectivelyacross certain of said pairs of outlet terconnected to one terminal oi' a pair of outlet terminals and having the other lead connected to said neutral wire. y

2. ln an electric iangecircuit; power input leads including a neutral wire and two hot wires; a plurality of separate heating unit circuits including manual Switches connected across said leads; a multi-pole double-throw switch having one set of iixed poles connected to one hot wire; a single pole timer; the other ii'xed poles of Ythe switch being connected through the timer to the same hot wire; the movable poles of the switch being respectively connected in the separate heating unit circuits; means for selectively engaging any one of the movable poles oi the switch with its related i'lxed pole of the second set while retaining the other movable poles oi' the switch engaged with their related fixed ypoles of the first set; a motor; one o said separate circuits including a plurality oi multi-heat selectors operated by said motor and connected across said hot wires through the related movable switch pole, each selector having a pair of outlet terminals; manually controlled means in said selectors for varying the average thermal output over a period of time across each of said pairs of outlet terminals; ,surface heating units connected respectively across certain of said pairs of outlet terminals, and a convenience outlet having one lead connected to one terminal of a pair of outlet terminals and having the other lead connected to said neutral wire.

ROBERT T; FRAZIER.

I-Iowever, since the pairs o switch con- 

